Protection of metal surfaces from corrosion



' Patented-Oct. 3, 1944 r UNITED STATES PATENT orrlca PROTECTION OF METAL SURFACES FROM CORROSION Ralph Forder Denington, Slough, England, as-

signor to Imperial Chemical Industries Limited, a corporation of Great Britain No Drawing. Application February 6, 1942, Serial N 0. 429,806. In Great Britain March 31, 1941 7 Claims. (01. 148-6) This invention relates to the protection of sur-' faces of metals against rusting or corrosion and to compositions suitable therefor. The invention relates particularly to the temporary protection of iron and steel against rusting during transit or storage, and during erection prior to painting.

acetone, oleyl acetone, pelargonyl acetone, phenyl acetyl acetone and undecylenyl acetophenone.

The invention is illustrated by but not limited to the following examples.

It is well known that surfaces of ferrous metals Y may be prevented from corrosion or rusting by applying thereto a temporary coating of a waterproof material. clear lacquers or non-volatile oils, fats or greases, non-volatile in the sense that theycan be applied to metal surfaces and do not evaporate under normal conditions of storage or transport. Mineral oil affords protection for a limited time only while in the case of thick greases such as lanoline a relatively deep layer is necessary to give appreciable protection.

We'have now found that ,S-diketones have the property of reacting with iron compounds and remaining organophilic, and that when a small proportion of such. a compound is applied to'a metal surface, a protective layer is formed. Thus, if a proportion of such a compound is Example 1 2 per cent of undecylenyl acetone was dissolved in toluol and poured on toa part of; the

. surface of a steel panel exposed in the open air.

These coatings may consist of I after one month.

incorporated into a waterproofing material capable of being used as a temporary rust preventative, there results a composition of greatly enhanced value.

According to the present invention, therefore,

surfaces of metals are protected against corro sion or rusting by application to the said sur-' faces of a composition consisting of or containing a p-diketone. The p-diketone may be applied as such or dissolved in a volatile organic solvent, and a surface so treated can subsequently be painted or lacquered without removing the protective film of the p-diketone. Alternatively the p-diketone can beapplied, together alkyl or aryl or aralkyl groups, and may be similar or dissimilar. Examplesroi such compounds are undecylenyl acetone, oenanthyl acetone, caproyl acetone, capryl acetone, caprylyl It was found that corrosion 'of the steel commenced after 24 hours except on the area covered by the undecylenic p-diketone. This area showed no rust for 14 days.

Example 2 5 per cent of undecylenyl acetone was dissolved in thick gear oil and spread on a bright steel water-cooled surface. Under conditions of varying humidity, temperatures and condensation during a Period of nine months no signs of corrosion were observed. Similar surfaces treated with gear oil alone showed spots of rust Example 3 A composition comprising 20 parts by weight of lanoline with 2 parts byweight of undecylenyl acetone and 78 parts of petroleum distillate of boiling point within the range of 160 C. to 180 C. was applied to a clean mild steel surface exposed to weather. After ten week the film was removed with heavy naphtha,.when it was found that the metal was bright and corrosion-free.

By contrast a clean mild steel surface treated with a solution of lanoline in petroleum distillate showed appreciable corrosion.

Example 4 A composition comprising?!) parts by weight of lanoline, 2 parts by. weight of undecylenyl acetone andi'lB parts by weight white spirit when applied to clean mild steel and the solvent allowed to evaporate gave considerably reater protection than that obtained by the use of a lanolinesolution alone. I

Example 5 Parts by weight Chlorinated rubber 25 Oleyl aceto 5 Heavy naphth 45 Toluol 20 Benzol 5 The chlorinated rubber was dissolved in the other components by stirring. Theresulting composition was applied by brushtoa steel girder which was left exposed to the weather for a period of five months. On then removing the film by application of heavy naphtha the metal surface was found to be quite free from corrosion.

I claim:

1. A method of protecting metal surfaces against corrosion by exposure to the atmosphere which comprises applying to said surfaces 9. com

position comprising a p-diketone.

2. .A method of protecting metal surfaces against corrosion by exposure to the atmosphere which comprises applying to said surfaces a, composition comprising a B-diketone and a volatile organic solvent.

3. A method of protecting metal surfaces against corrosion by exposure to the atmosphere which comprises applying to said surfaces a composition comprising a p-diketone and a material selectedfrom the group consisting of non-volatile oils, fats, greases, mixtures of said materials, and

solutions of said materials.

which comprises applying to said surfaces a composition comprising oleyl acetone.

6. A method of protecting metal surfaces against corrosion by exposure to the atmosphere which comprises applying to said surfaces acomposition comprising lauryl acetone.

7. A composition for the protection of metal surfaces against corrosion by exposure to the atmosphere which comprises oleyl acetone and a material selected from the group consisting of non-volatile oils, fats, greases, mixtures of said materials, and solutions of said materials.

RALPH FORDER DENINGTON. 

